Herein a lattice-matched hexagonal/rhombohedral ZnIn2S4 homojunction was constructed to boost photocatalytic performance. The ZnIn2S4 homojunction was prepared by in situ growing the hexagonal ones on the surface of rhombohedral nanosheets via the hydrothermal method. The coherent growth of the (110) planes occurred for hexagonal and rhombohedral ZnIn2S4 due to the lattice-matched plane. The as-prepared homojunction has an II-type band alignment. Under visible irradiation, the removal rates of methyl orange and Cr (VI) within 30 min reached 93.6% and 98.8%, respectively, and the rate constants of methyl orange removal are nearly 7.8 and 3.6 times that of hexagonal and rhombohedral ZnIn2S4, respectively. The characteristics of the coherent lattice plane and II-type band alignment promoted the efficient transfer and separation of photogenerated carriers for the as-prepared ZnIn2S4 homojunction. It boosted the photocatalytic performance of the homojunction catalyst. This work provides an efficient strategy for inhibiting the recombination of the photogenerated carriers to construct an efficient photocatalyst.